yeah, calculations is 1 side, understanding the relevance to your build/situation is the other side…
2 rules i try to follow:
1: The higher the nozzle airspeed = higher pull needed to generate that speed = better gas-quality but less gas filling the engine cylinders = less power from the gasifier…
( counter that with bigger engine as needed or with a designated blower )
2: understand the limiting factor from slag forming… what fuel causes what amount of slag.
If you are running hot, add some water or exhaust return,
As i am the spoiled one, having tools to measure some effects, i just can point out to the many good advices given by other dow members, based on their experiences.
My few tools actually proved their points…
Another point: turn down ratio, how you calculate that into your build design ?
Low level gas flow and high flow need.
I toggled that problem with multi nozzle systems, changing the flow ratio based on vacuum from/on the engine/gasifier.
Few of the many persons i learned from; WK’ts design’s/concepts of thinking, Gary Gilmore simple fire, Steve U’s understandings of internal functioning of engines.
Some people wants to use other birds feathers as their own, i am kinda allergic for such, hence less active in commenting.
Many of the builds i have seen on this forum i consider them as pieces of art… my 2 thumbs up to those.
That list is actual long…
Artist Copyright ?
I just went to have a look at that spreadsheet…
Yeah, if people keep editing the original instead of downloading a copy…
The whole calculations are gone, i will replace with an original copy and repost a link
Here is the latest Charcoal Gasifier Nozzle Design Comparison file, with the results from Koen’s repaired spreadsheet. Results from the Kaupp/Goss “Method 1” are basically pretty close to those from Koen’s spreadsheet.
Will think a bit more about turndown, but it looks like a 1.25" to 1.4" single nozzle is appropriate, for this application.
Been busy shredding Goatweed, Senna Beans, Horsemint and a few other unwelcome plants which sprung up from the 25 plus inches of rain we had in April and May, After that, though, it quit raining and we’ve had essentially 100 degree days for 5 plus weeks, now. Anyway, I got tired of waiting for it to get cooler, and am making progress on the “Paynerick Plate”. Decided to go with a 1.375" nozzle hole. Should have it done in a week or so.
Behold, The Paynerick Plate! Finally! 1.375" nozzle hole in 1" plate, welded to a section of 6" x 3/8" wall square tubing. Lighting, water and air will be via the 3" NPT fitting welded to the other side … now to build the hopper. Going to be 106 F tomorrow. Hottest summer I have experienced. Cows are getting skinny. Fed first bale last week, second this week. Pray for rain. Maybe next week, they say.
That plate nozzle should hold up to the heat and dissipate it. Is the box part going to be exposed to the out side ambient temperatures on the out side of the gasifier barrel? If so welding fins on the out side of the box will help it work even better in dissipation of the heat.
Thanks for that idea! However, only the side of the box with the 3" NPT fitting will be exposed to ambient, and there is not a lot of surface area there. Hopefully the vaporization of the water drip onto the plate/into the box, and the subsequent quenching of the fire by the water vapor to below incandescent - will handle enough of the excess heat.
A few years ago I welded this 1" square tubing “space frame” to contain a 55 gallon bbl based charcoal gasifier, for this truck. Now I am thinking - why not just seal weld 16 gauge or so steel over the OD of it, turn the whole thing into the hopper/gasifier - with a puff lid of course?
If it were a woodgas gasifier I would be a little more hesitant to go this large, since woodgas puffs can be more violent. But for charcoal I think it will be OK. Any comments?
The Paynerick Plate will be about in this position, about a third of the way into to gasifier, anticipating say a 12 inch fire in the center. It will also be about 12", maybe a little less, off the bottom.
I have only had one puff, and it blew out of my nozzle instead of the lid. Scared the heck out of me but didn’t do any damage.
I would maybe consider having 1/4" plate facing opposite of the nozzle, just in case, just a 12"x12" square. It’ll most likely just come up diagonally though. Maybe do a ceramic or mineral wool blanket around the lower 1/4 of the gasifier and bottom, too. Could skin that with some flashing.
I like it. Just wondering about the location of the gas outlet? With all of that extra space around and below the tuyere, perhaps there is potential for a cross-draft. Or an inner wall to form a channel through which to pull gas down from the top for a bit of cooling or as an internal drop box for dust collection?
If this square box is going to be the gasififer charcoal area, then when you are under a vacuum of let’s say 30+ it will could bend the metal sides. This happen on plastic barrels that are not strong enough to handle the higher vacuum negative pressures. Steel barrels can handle higher vacuum negative pressures. Not sure if this is going to be a one piece slide in unit or not with the filter part too.
At 258 gallons I think you could likely go anywhere you wanted on one fill-up.
At an ultra conservative estimate of 1:1 lbs per mile on my charcoal density you’d get 300 miles if it could burn down to the nozzle. I’d say a safe 200 miles stop and go driving.
Maybe 400 miles highway driving. Crazy to think about.
Cody, looking at the area of charcoal place if it is the total area to the nozzle, you need to look at it with a 60° cone angle to the nozzle from the top. This will be you actual charcoal useable fuel. This is not the full square footage of this area. Even in a 12" fire tube opening with a 55 gallon barrel hopper some of the charcoal fuel gets stuck in the upper hopper if it does not have a 60 ° cone shape in the bottom of the barrel hopper.
Thanks! Was going to stick with the old updraft model. Thought about cross-draft or down-draft, and maybe I should think some more. I liked the cooling aspects of the updraft, and consistent gas quality, but maybe with this much room, move the tuyere up and downdraft it???
Good thought, Bobmac. I do have some bracing on the sides, but I should evaluate it. 3" NPT inlet should move some air, though. Filter will be separate, outside the box.
